F4 SLICE-1: typed proposals[] on shared anchors/Provenance (spec §6.3, INV-13) (#12)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/model.ts

@@ -61,6 +61,22 @@ export interface AttributionRecord {
   turnId?: string;
 }
 
+/** F4 (spec §6.3, INV-13): a PENDING machine edit — state, not history. */
+export interface Proposal {
+  id: string;
+  /** shared anchors map; fingerprint.text IS the exact target text (INV-11). */
+  anchorId: string;
+  /** the full proposed text for the anchored range. */
+  replacement: string;
+  author: Provenance;
+  /** ISO-8601. */
+  createdAt: string;
+  /** groups N proposals born of one live turn. */
+  turnId?: string;
+  /** what the human asked for (review context). */
+  instruction?: string;
+}
+
 export interface Artifact {
   schemaVersion: number;
   /** repo-relative path; the sidecar key. */
@@ -70,8 +86,8 @@ export interface Artifact {
   threads: Thread[];
   /** F3 fills this (spec §6.3, INV-4): typed attribution records anchored via anchors[]. */
   attributions: AttributionRecord[];
-  /** F4 extension point — reuses anchors[] + provenance; not in F2. */
-  proposals: unknown[];
+  /** F4 (spec §6.3, INV-13): pending proposals on shared anchors[] + Provenance. */
+  proposals: Proposal[];
 }
 
 export function emptyArtifact(docPath: string): Artifact {
@@ -139,7 +155,15 @@ export function serializeArtifact(a: Artifact): string {
       updatedAt: at.updatedAt,
       ...(at.turnId !== undefined ? { turnId: at.turnId } : {}),
     })),
-    proposals: a.proposals,
+    proposals: a.proposals.map((p) => ({
+      id: p.id,
+      anchorId: p.anchorId,
+      replacement: p.replacement,
+      author: serializeProvenance(p.author),
+      createdAt: p.createdAt,
+      ...(p.turnId !== undefined ? { turnId: p.turnId } : {}),
+      ...(p.instruction !== undefined ? { instruction: p.instruction } : {}),
+    })),
   };
   return JSON.stringify(canonical, null, 2) + "\n";
 }